Why would I add python to PATH

Question

I am beginning to look at python, so when I found a tutorial it said that the first thing to do would be to download python from www.python.org/downloads/

Now when I downloaded python 3, I then started the installation and got to

Why would I want to "Add Python 3.5 to PATH"? What is PATH? Why is it not ticked by default?

Answer 1

PATH is an environment variable in Windows. It basically tells the commandline what folders to look in when attempting to find a file. If you didn't add Python to PATH then you would call it from the commandline like this:

C:/Python27/Python some_python_script.py 

Whereas if you add it to PATH, you can do this:

python some_python_script.py 

Which is shorter and neater. It works because the command line will look through all the PATH folders for python and find it in the folder that the Python installer has added there.

The reason it's unticked by default is partly because if you're installing multiple versions of Python, you probably want to be able to control which one your commandline will open by default, which is harder to do if both versions are being added to your PATH.